This invention relates to a piston protection system for an internal combustion engine and more particularly to an improved apparatus and method for predicting when an engine may be operating in a detrimental state and taking steps to prevent damage to the engine.
It is known to employ knock detectors with internal combustion engines so as to sense when a knocking condition is occurring and take precautionary steps to reduce or stop this knocking. However, in addition to engine knocking, there are other operating conditions that can cause detrimental operation. For example, it is known that the forces on the piston during its reciprocation are such that the piston tends to rock about the piston pin and can scuff the cylinder walls. Under extreme conditions, damage to either the piston and/or cylinder walls can occur. In fact, under extremely aggravated situations, there can actually occur seizure of the piston in the cylinder bore.
Previously, it has been the practice to try to limit the speed of the engine so as to reduce the likelihood of damage under this situation. However, the protection against this problem has always had to be in the basic design of the engine. That is, it was heretofore impossible to predict when the engine running conditions were such that piston or cylinder bore damage of the aforenoted type might occur. It has been discovered, however, that sensing of the vibrations of the engine itself can be predictable in indicating when the engine is operating in a condition that such piston/cylinder bore damage might occur. It has been found that by measuring the vibrations of the engine and comparing them with known or predicted data, protective steps can be taken which will reduce the likelihood of such damage.
It is, therefore, a principal object of this invention to provide a method and apparatus for predicting when engine operating conditions can reach a detrimental stage and taking precautionary steps before damage occurs.
It is a further object of this invention to provide a method and apparatus for detecting the possible occurrence of piston/cylinder bore damage and taking measures to protect against such damage during the engine running.